Metalic textures not rendering
Yes,I feel nothing to reflect might be your problem.

You can use an HDR to check reflections and lightings. Just a google search would help, or just go to https://hdrihaven.com/ or http://www.hdrlabs.com/sibl/archive.html

You can get some free HDR and just plug the .exr into "world" shader-node.

This would solve issues if some are there with your scene itself.

You can also try checking the screen-space reflections box in the render options. Might help. I would uncheck half-res to hoping that no half-res makes it full-res.